TGFB1 and pulmonary arterial hypertension: MiRNAs have recently gained importance in the pathobiology of PAH, and at least some seem to play a role in the regulation of the BMP/TGFβ pathway (e.g., miR-140-5p activates BMPR2, while the miR-130/301 family upregulates the pro-proliferative TGFβ route) [73,76].